One vertex per element, one color per generator, with an edge from x to x·s.
(2,4)(6,9)(7,11) involution — undirected(5,6)(7,10)(8,9)(11,12)(14,18)(15,21)(16,23)(19,24)(20,26)(22,27) involution — undirected(1,2,3,4)(13,14,16,18,17,19,23,24)(15,20,21,25,22,26,27,28)(5,7,8,11)(6,10,9,12)(14,19)(18,24)(20,26)(25,28)(6,9)(10,12)(13,15,16,21,17,22,23,27)(14,20,18,25,19,26,24,28)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.